Announcing a new version of SecureChat

I’ve just checked in a new version of SecureChat on the main branch at GitHub.

New features include:

  • A working Android client.
  • Various notification bug fixes.
  • Various iOS bug fixes.

Why am I doing this?

Even after all these months, since the Apple v FBI fight began, I’ve been hearing way too much stupidity about encryption. The core complaint I have is the idea that somehow encrypted messaging is the province of large corporations and large government entities, entities that must somehow cooperate in order to assure our security.

And it’s such a broken way to think about encryption.

This is a demonstration of a client for iOS, a client for Android and a server which allows real-time encrypted chatting between clients. What makes chatting secure is the fact that each device generates its own public/private key, and all communications are encrypted against the device’s public key. The private key never leaves the device, and is encoded in a secure keychain with a weak checksum that would corrupt the private key if someone attempts a brute-force attack against the device’s secure keychain.

Meaning there is no way to decrypt the messages if you have access to the server. Messages are only stored on each device, encrypted using the device’s private key–meaning a data dump of the device won’t get you the decrypted messages. And a brute force attempt to decode the device’s keychain is more likely to corrupt the keychain than it is to reveal the private key.


Security is a matter of architecture, not just salt that is sprinkled on top to enhance the flavor. Which is why there are so many security breaches out there: because most software architects are terrible at their job: they simply do not consider the security implications of what they’re doing. Worse: many of the current “fads” on designing client/server protocols are inherently insecure.

This is an example of what one person can do in his spare time to create a secure end-to-end chat system which cannot be easily compromised. And unlike other end-to-end security systems (where a communications key is generated by the server rather than on the device), it is a protocol that cannot be easily compromised by compromising the code on the server.

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